Anyway. I have some bids in it, right. Then lunch time, out of the blue, some joker sends a limit order to sell 5'000 into the live order book (it's traded 150 shs at this point). He/she clearly had the wrong stock, cos this one was trading in the mid 400s and the limit on the 5000 to sell was at 77 or something like that. Completely off.
The order took out 560 shares or so. 300 mine. Then the stock was stopped limit down 2%. The sell order was then retracted. At that point I was sure that it was a mistake. Someone mistyping a ticker. I immediately put limit orders in the book where I'd bought stock to protect my price.
In some cases the sell order could attract further sell orders, as a lemming effect sets in. That's why I immediately put in buy orders. To let the market maker know there's demand at those price. Also anyone with a Bloomie can see what was on offer at what price to get the stock stopped. So I was pretty confident the trader who entered the sell order would quickly cover.
But he didn't. He just put bids in around where he'd sold. So I bid the stock a bit higher. Nothing happened. Suddenly I get hit and am now holding 500 shs. Decided to take out the nearest offer and print a .8% higher price (2-3% above where seller had knocked out his shares) - holding 620 shs. That finally did it. The algo trading machines slowly started putting in bids now (alongside where I had been biding). 10-20 minutes not much happened. Then I saw larger bids coming in and started knocking out the shares I'd been dealt. The earlier mistaken seller was biding I was sure, as it wasn't the market makers usual size.
All in all just over 1k for my troubles. But interesting to "play" against a real human.